Coating-impregnating chamber for catalyst support members

ABSTRACT

A liftable housing form of pressure tight treating chamber is especially adapted to providing multiple stage treatments to catalyst support members, such as honeycomb-type elements, in order to place a catalytic coating on all of the interior surfaces of the multiple passageways through the elements. Power operated lifting of an open-bottomed housing permits the placement of members on sharp edged pin support means in the interior of the chamber such that passageways will not be blocked while the element is being subjected to vacuum, liquid coating, and air blowing stages.

The present invention relates to an improved type of treating chamberwhich will provide for the multiple stage treating of catalyst supportmembers to effect a catalytic coating thereon.

More specifically, the invention is directed to a special form ofpressure tight chamber for handling multiple treating streams and whichwill have a liftable housing and lower internal pin support means toaccommodate the insertion and removal of a catalyst supporting unit,such as a honeycomb type of element, in an elevated position to receivean unblocked, full flow-through of the various treating streams in thesuccessive stages.

The need to remove or convert the noxious components in vehicularexhaust gases is now well known as a means for overcoming air pollution.Also, the present and proposed future requirements for having catalyticexhaust gas converters on motor vehicles are quite well known. Thecatalysts for the various forms of converters are, at this time, beingmanufactured and supplied in two general forms, namely: (1) ascatalytically coated rigid skeletal monoliths, or honeycomb type ofelements, where there are a multiplicity of longitudinal passageways ineach unit in order to provide a high surface area; and (2) as confinedbatches or beds of catalytically coated particulates which, in turn, maybe generally spherical or of small pellet form, with nominal diametersand lengths in the 1/16 to 5/16 inch range.

The spheres and pellets are of advantage as catalyst support material tothe extent that they can be made from refractory inorganic oxides,typically of alumina, or of alumina with one or more other oxides asadditives to help stabilize for strength, heat resistance, etc., suchthat they have surfaces with high porosity and large resulting actualsurface areas as compared to the more dense "ceramic" monoliths. On theother hand, pills and pellets are far more fragile than the rigid,monolithic type of honeycomb elements and are more easily broken whenplaced in service on an auto or truck. The small spheres or pellets areespecially subject to exhaust gas pulsations from the engine operationsuch that a breakage rate can be quite high for loosely packed beds ofthese rather fragile members. The rigid monolithic, honeycomb structuresare typically made from "ceramics" which comprise refractory crystallinematerials such as sillimanite, magnesium silicates, zircon, petalite,spodumene, cordierite, aluminosilicates, mullite, or combinationsthereof, etc. Such materials are generally considered to have a poroussurface; however, as heretofore noted, their surfaces are not highlyporous to the same extent as obtained with a lower bulk density aluminapill or extrudate and it is generally advisable to provide an aluminacoating over the skeletal structure prior to effecting surfaceimpregnation with the catalytically active component. These monolithic,substantially catalytically inactive crystalline support members havebeen described in prior art patents, as for example in Keith et al. U.S.Pat. Nos. 3,331,787 and 3,565,830, such that it is not deemed necessaryto describe them in detail herein.

Typically, the catalytic component will comprise a noble metal such asplatinum or palladium, or a mixture thereof, for providing a highlyactive oxidation catalyst; however, other active metals may will be usedto provide a particular type of catalytic coating. Actually, it is notintended to limit the present invention, which is being directed tocoating apparatus and to coating systems, to any one specific type ofcatalyst coating or coatings, inasmuch as oxidation catalyst materialsmay comprise the metals of Groups I, V, VI and VIII of the PeriodicTable, particularly copper, silver, vanadium, chromium, iron, cobalt,nickel, platinum, palladium, with a component being used singly or incombination with one or more other active component.

Reducing coatings may comprise oxides of copper or of copper-iron,copper-nickel, etc., as well as platinum group metals.

While the use of catalyst coatings on particulates and on rigid skeletalelements, as well as various methods of applying coatings, have beenknown for some years, there is no knowledge of prior art apparatus andsystems suitable for effecting a high volume production of catalyticallycoated elements suitable for use in automobile exhaust gas converters.For example, the aforementioned U.S. patents set forth various methodsfor coating a refractory honeycomb type of member with alumina and anactive catalytic coating. However, dipping and spraying operations arenot nearly rapid enough to provide a good assembly-line productionsystem which will permit, for example, the coating of an element withalumina, or the catalytic impregnation of a coated element, in a timeperiod of less than 11/2 to 2 minutes. Also there have been no knownprior art teachings with regard to using vacuum treating on a rigidskeletal member in order to more rapidly degassify or "out-gas" thesubstrate and provide an improved fast coating procedure.

It is thus a principle object of the present invention to provide aspecial chamber which will make possible the rapid multiple stagetreatment of catalyst elements such that they can be catalyticallycoated in an optimum manner.

In another aspect, it is an object of the invention to provide apressure tight chamber such that there can be vacuum treating of supportmembers, as well as a subsequent pressurized air blowing of coatedmembers.

It is also an object of the present invention to provide a special formof chamber construction and design which will permit a short contacttime between the coating stream and the element, as well as shortcontact times for air or other fluid streams which are to be broughtinto contact with an element.

Still another object of the present invention is to provide a multiplechamber arrangement, such as a multiplicity of chambers on a moving beltor rotating table unit, whereby a multiplicity of chambers can, in turn,handle a multiplicity of elements at one station or general locale.

In one embodiment the present invention provides a treating chamber foruse in effecting the multiple stage treatments of catalyst supportmembers to provide a catalyst coating thereon, which comprises incombination, an open-bottomed liftable housing section, power operatedmeans connective to such section for effecting the periodic liftingthereof, a base section, a seal means for accommodating the lowerperiphery of said housing section and for providing a pressure tightseal between said two sections, spaced support pins projecting into thelower central portion of the zone above the base section and providingfor an unobstructed fluid flow through a catalyst support member whichis placed therein, a fluid drain means from said base section within theconfines of said liftable housing section and said seal means, valvemeans for said drain means, at least one conduit means to the upperinterior portion of said housing whereby fluid steams may be broughtinto the interior of said housing and into the passageways of saidmember to effect a thorough contacting of the surfaces thereof, andvalving means for said conduit means to regulate various fluid flows tothe interior of said chamber.

In a quite broad aspect relating to effecting the coating of a rigid,ceramic honeycomb type catalyst support member, there is provided animproved method of coating by subjecting the member to vacuum treatingjust prior to its being contacted by the coating material, whereby therecan be a rapid, improved coating placed on the member.

In another more specific embodiment, the present invention will providean apparatus for effecting the rapid and uniform coating of catalystsupport members, in a manner which comprises the steps of: (a) placingthe member(s) in a pressure tight chamber; (b) exerting a vacuum on themember(s) to remove entrapped air from surface pores; (c) while havingthe member(s) in a degassed condition, effecting the filling of thechamber with a desired coating solution; (d) maintaining a short periodof super-atmospheric pressure on the thusly filled chamber to insure thefilling of pores; (e) subsequently effecting a release of pressure andthe removal of the encompassing solution; (f) providing the blowing ofpressurized air over the surfaces of the thusly coated member(s) toremove excess solution and to preclude any undesired passagewayblockages; and then (g) effecting removal of the resulting coatedmember(s) from said chamber.

The present apparatus is particularly directed to effecting the coatingof rigid skeletal structures, such as honeycomb-type elements with amultiplicity of small parallel passageways; however, the same equipmentand method of operation may well be utilized to advantage in connectionwith effecting the rapid catalytic coating of contained beds, orbatches, of subdivided catalyst support particulates such as smallspheres or pellets which have been formed of refractory inorganic oxidematerials.

Typically the outer pressure tight housing for the chamber will beconstructed and arranged so as to be lifted by an air cylinder or otherfluid power motor means and will have an O-ring or other suitable gasketmeans on or engageable with its lower periphery to effect a pressuretight seal with a base member. The housing will be liftable for asufficient distance to effect the insertion and removal of a catalystsupport element which will undergo the various treating stages to effecta rapid and efficient coating operation. The lower interior portion ofthe chamber will also be provided with suitable sharp edged elementsupporting pins upon which the element can rest without having undueblocking of any of the passageways. For a honeycomb type of element, itwill preferably be inserted in a manner to be positioned with verticalorientation for its plurality of passageways, whereby there can be adownward flow of coating materials through the passageways and asubsequent downward blowing of pressurized air therethrough, wherebyexcess fluid will be forced into a lower drain arrangement to effect theremoval of coating materials not adsorbed by the surfaces of eachelement.

A preferred form of chamber will also have a flexible ring or gasketmeans which will project laterally inwardly from around the interiorperiphery of the chamber at a height which will slightly overlap theupper peripheral edge of an inserted element and substantially precludea downward flow of treating fluid streams around the outside wall of theelement and within the annular space between the outside wall of theelement and the inside wall of the chamber. In other words, for ahoneycomb type of element all fluid streams will be channeled into themultiplicity of passageways which will eventually be utilized forconversion purposes in a particular converter or reactor.

Also, a fluid stream distributing section is desirably provided in theupper portion of the chamber such that there will be substantiallyuniform flow down through the chamber for its full cross-sectionalwidth. A single fluid inlet to the upper portion of the fluiddistributing section may be provided or, alternatively, a plurality ofinlets may be provided so as to independently introduce the varioustreating streams for the sequential stages of treatment. Although not apart of the present improved lifting-wall form of chamber, a preferredsystem of operation will provide for automatic valving (through the useof rotating valve means or otherwise) which will effect the sequentialflow of the different fluid streams to the chamber itself. For example,there may be the sequential provisions for vacuum and degassification ofan element; the flow of treating fluid; pressure application to a filledchamber; and, high pressure air blowing to effect both a removal ofexcess fluid and a partial drying of the coating on the element. Inconnection with the valving arrangement, there will, of course, besuitable timing means in order to effect the desired periods of contactfor each of the sequential streams as well as timing for the raising andlowering of the chamber wall to provide for the insertion and removal ofthe element.

A single pressure tight chamber may be designed and constructed toaccommodate more than one rigid skeletal element, or more than onecontainer means for a batch of subdivided catalyst support material.Also, as will hereinafter be described more fully, there may be anapparatus arrangement, such as through the use of a rotating tablemeans, where a multiplicity of chambers are provided in one area in amanner to effect the sequential treating of a plurality of catalystsupport means so as to have a continuous assembly-line operation. Inother words, an element can be loaded into a chamber (as one of aplurality of chambers) from which the previously coated element has beenremoved and the chamber then rotated in a circle through timed stageswhere there will be closing of the chamber and subsequent sequentialopenings and closings of valves to effect the desired sequential stagetreating of the enclosed element whereupon completion of the circlethere will be an opening of the chamber and an unloading of a treatedelement whereby the chamber will then be reloaded at the nextincremental movement of the table to provide a treating cycle foranother element. Depending upon the size or diameter of the particularrotating table, any convenient number of chambers may be mounted to inturn provide for the treating of a multiplicity of elements at the sametime, but with each element being one stage behind a previously loadedelement with respect to the direction of rotation for the table.Although a rotating table arrangement seems preferable and of advantagein a high production operation, there may also be suitable multiplechamber treating operations where the individual chambers are beingutilized in straight line operatons utilizing straight line conveyormovement means. Alternatively, there may well be batch operations wherea plurality of chambers are loaded simultaneously so as to provide forsimultaneous treatment of the encased catalyst support members.

As heretofore stated, there have been no known procedures or knownapparatus which provide for a vacuum treating of the ceramic typecatalyst support members in order to preclude the trapping of air insurface pores and as a means of insuring the rapid flow of a coatingslurry or solution into the interior of the surface pores. Although allof the advantages may not be presently understood, it does appear that agreater quantity of coating material can be placed on a support memberfollowing a vacuum, degassing operation, in comparison to dippingoperations. It is also believed that there may be better or morecomplete filling of pores so as to hold a greater quantity of coatingmaterial as well as perhaps obtain a better binding or "locking" of thecoating material onto the surface of the element.

A pressure tight chamber is not only of advantage in permitting a vacuumoperation, but is particularly helpful in permitting the pressurized airblowing of members following the coating stage. The high pressure airstream can rapidly remove excess slurry or solution from the membersurfaces and preclude the blocking of small honeycomb channels beforethe coated support member has a chance to be fully dried.

Reference to the accompanying drawings and the following descriptionsthereof will serve to assist in illustrating the design and operationaladvantages of a chamber adapted to hold a single support element, aswell as illustrate how a plurality of chambers may be arranged on arotating table means to provide for the sequential treatment of amultiplicity of elements at the same time.

Specifically, FIG. 1 of the drawing shows a cross-sectional elevationalview through a single element holding chamber which is provided with alifting housing construction to in turn permit the rapid insertion andremoval of a rigid skeletal element.

FIGS. 2 and 3 illustrate in, respectively, plan and elevational viewshow a plurality of chambers may be arranged on a rotating table supportmeans to provide for the sequential and stage-wise treating of aplurality of elements in a rapid continuous manner.

Referring now particularly to FIG. 1 of the drawing, there is shown apressure tight chamber having a lifting wall or housing section 1 withtop sections 2 and 3. A lower base section 4 is shown as being providedwith an O-ring seal member 5 in groove means 6 such that the lower endportion of housing section 1 can effect a pressure tight seal with thebase member. Alternatively, a suitable gasket or seal ring means couldbe attached to the lower end of wall section 1.

On the upper plate or top member 2 there are provided upwardlyprojecting flange members 7 to accommodate pin means 8 which will, inturn, connect with a piston rod means 9 for piston member 10, wherebythe latter can periodically effect the desired raising and lowering ofthe entire upper chamber portion including the housing wall portion 1such that a catalyst support element, indicated at 11, may be insertedinto the interior of the chamber, as well as removed therefrom, for thecoating operation.

Also in accordance with the present invention, pin support means such aspointed top pins 12, are provided to support the catalyst element 11 sothat the passageways through an element will not be blocked with slurryor other coating materials. Also, spaced apart pins will permit elementlifting blades to be inserted between pins and provide for themechanical placement and removal of a support member from the supportpins. In the present instance, pins 12 are mounted from base member 4and are centrally located in order to, in turn, provide for the centralpositioning of an element 11. Preferably, the pins are removably mountedsuch that different length pins could be used where needed toaccommodate a different height element to be treated in the chamber, orbe removed and replaced after excessive wear. Base member 4 is alsoprovided with a sloping surface portion 13 tappered toward a centralopening 14 providing for an outlet port from the treating chamber. Asuitable outlet nozzle means 15 is also indicated as being providedwithin a supporting table or platform 16 whereby there can be a fluidoutlet conduit means or other suitable passageway means carried to ablow-down tank, not being shown in the present drawing. For constructionand assembly purposes, bolts 17 are indicated as attaching base plate 4to the table or other support means 16.

Various methods of construction may be utilized in connection witheffecting the detailed design and construction of the present improvedform of chamber; however, as shown in the present drawing, a pluralityof internal pieces are utilized to provide for the introduction of thevarious fluid streams by way of a single fluid inlet passageway 18. Thelatter is provided within the upper head section 3 while a wide andshallow fluid distributing zone 19 is provided above a perforatedtransverse portion 20 in a separate plate section 21. The latter is, inturn, clamped between a lower internal cylindrical section 22 and thelower face of the upper section 3 by means of spaced long bolt members23. Fluid sealing members, such as O-rings 24 and 25, are indicatedaround the clamping bolt members 23 at the interface between members 21and 3, as well as between the lower face of 21 and the cylindricalmember 22, in order to preclude fluid leakage into the bolt passageways.

Also, as previously noted, the preferred arrangement provides for aflexible seal ring 26 at a location within the chamber to lap around theupper peripheral edge of a support member, such as 11, which will beintroduced into the movable wall chamber for treating and coating.Specifically, the flexible seal member 26 is indicated as being clampedaround the lower edge of cylindrical member 22 by means of clampingmember 27 and spaced bolts 28. In the event that screens or otherperforate container means would be utilized to hold a batch of pills orpellet-form catalyst support members in a position indicated by thedashed lines 11, in a manner similar to the positioning of a rigidskeletal member or honeycomb element, then flexible seal member 26 mayhave a somewhat different configuration, or perhaps be eliminated, tobetter accommodate fluid stream flow into and around the subdividedcatalyst support elements. It will also be noted that plug means 29 withO-ring means 30 have been shown in the recesses or drilled holes 31accommodating the heads of bolts 23 so as to preclude fluid flowupwardly around the bolts 23 when the chamber is being pressurized. Inorder to have the present pressure tight chamber accommodate differentsized, or different shaped members, there may be the replacement ofinternal member 22 or perhaps members 26 and 27, so as to fit aparticular sized catalyst support element.

As a part of the overall system to be used with the present movable wallchamber, the drawing indicates a conduit means 32 connecting throughnipple means 33 to fluid inlet port 18 within the upper portion of thechamber and such conduit means 32 also being connective with a multipleport valving means at 34. The latter is indicated diagrammatically asproviding means for separately introducing various treating fluidstreams into conduit 32 and into the treating chamber, as for example: apressurized air stream from inlet 35; a vacuum treating stage from port36; and a fluid treating stream by way of nozzle 37. A mechanically orelectrically operated rotating valve stem or cam operated, spring biasedvalve plugs, etc., may be utilized in connection with the multiple portvalving means 34 to provide for the timed introductions of the varioustreating streams to the treating chamber and it is not a part of thepresent invention to be limited to any one type of manifold valvingmeans which would effect the sequential introduction of a plurality oftreating streams for various treating stages.

Also, it is not intended to limit the present invention to theutilization of any one type of construction materials for the presentimproved chamber inasmuch as the materials should be chosen toaccommodate the particular treating streams being utilized within thechamber. For example, if only non-corrosive materials are to be handled,then various types of metals and plastics may well be utilized for theinternal sections, as well as for the chamber wall construction. On theother hand, where the chamber is to be utilized for effecting a finalcatalyst coating or impregnating stage on support elements with anacidic impregnating solution, as for example, chloroplatinic acid and/orpalladium chloride, then the entire internal portions of the chambershould be constructed of acid resistant metals, such as tantalum, oracid resistant types of plastic, or of suitable plastic coated metals,whereby there will be a long life for the chamber under continuousoperating conditions.

With specific reference to FIGS. 2 and 3 of the drawing, there isindicated an arrangement where a plurality of chambers, such asillustrated and described in connection with FIG. 1 of the drawing, maybe utilized to provide for simultaneously and continuously carrying outtreatments on a plurality of catalyst support elements to thus result ina high production, continuous manufacturing procedure. In FIG. 2, whichprovides a partial plan view of a rotating table system, there isindicated by circles 38 an arrangement where a multiplicity of chambersmay be mounted on a rotating support table 39 to permit a continuousproduction system, with rapidly timed loadings and unloadings beingeffected to accomplish the desired high production coating procedure. Asbest shown diagrammatically in FIG. 3, an individual chamber at 38 isindicated as having its wall portion raised to insert an element 11' onpin support means 12' while at 38' there is indicated a closed chamberwith its wall means tight against base portion 4' and its enclosedelement still undergoing treatment prior to being removed at an"unloading station" which will be provided sequentially ahead of the"load station." In connection with each chamber 38 there will besuitable means for lifting its outer wall or housing section by an aircylinder means 10 and a fluid stream inlet conduit means 32, all asindicated diagrammatically and described in connection with FIG. 1 ofthe drawing. Thus, there will be a suitable mechanically operatedvalving manifold system at each of the zones 34' and each will have aplurality of suitably operated valving means to effect sequential timedfeedings of a desired stream through the conduit means 32 to theinterior of each chamber 38. In addition, there will be a suitablecentral fluid distributing means at 40 to take care of venting andaccommodate air, vacuum treating and liquid treating streams, such as atconduit inlet means 41, 42 and 43 and in turn sequentially distributingsuch streams through a plurality of conduits or flexible hoses 44, 45,46, 47 and 48 which will, in turn, be connective with the plurality oftimed valving means 34'. There is also indicated the utilization ofconduit or hose means 49 and 50 that are connective with the pluralityof fluid power cylinders 10 which will effect the raising and loweringof the movable wall sections of chambers 38 in accordance with a desiredtiming sequence.

Various structural aspects for the rotating table unit of FIG. 3 aremerely diagrammatic and should in no way be considered limiting withrespect to the present invention. For example, there are indicated aplurality of supporting posts 51 from rotating table 39 and a circularring-form plate means at 52 along with tubular-form support ring means53 to effect the supporting of the valving and superstructure means forthe upper portion of the rotating table assembly. There is furtherindicated the placement of an encompassing shield member 54 around theentire superstructure as well as around the plurality of treatingchambers 38. In connection with the rotating table portion 39 which isutilized to hold the plurality of base portions 4' for the chambers 38,there is additionally indicated the placement of spaced valving means 55which will start and stop flow from blow-down drain portions 14' foreach base section 4' whereby treating liquids as well as blow-down aircan be channeled into and through conduit means 56 to collector zone 57and from the latter through passageway or conduit means 58 to ablow-down drain area not shown. Various mechanical means as well asmotive power means may be used to effect the continuous or start andstop rotation of the table 39, as well as the entire superstructureassociated therewith, including the multiplicity of chambers 38 mountedabove table 39.

In connection with FIG. 2 of the drawing, which indicatesdiagrammatically the placement and use of a plurality of chambers 38 atspaced distances around the periphery of table 39, there is alsoindicated diagrammatically the utilization of conveyor means at 59 and60 to provide, respectively, for the unloading of treated elements 11'at an "unloading station" 61 by mechanically operated lift blade meansat 62 as well as the loading of elements 11' by means of blade means 63from a "load station" at 64. FIG. 2 further indicates diagrammatically,by virtue of dashed radial lines numbered (1) through (12), how thevarious valves connective with conduits 32 will be operated to effectthe desired stages of treatment for a catalyst support member within asingle chamber 38 as it is being rotated stage-wise in a timed manneraround with the rotating table member 39 from the load station at 64 tothe unload station at 61 (with the table rotation in this instance beingin a counterclockwise direction).

FIG. 2 is of advantage in also indicating certain segmental zonesbetween the radial dashed lines and the operating condition within thechamber for the particular segment. For example, there are indicationsas to when the chamber is being opened and closed; a segment for thetime period for which the chamber is under vacuum; the positioning whilethe chamber is being filled with treating fluid; fluid pressurization;and a blow-down of air to remove excess treating fluid and effect atleast a partial surface drying of the element prior to its being removedfrom the chamber and its placement on the conveyor means to be carriedto a further treating stage, to a packaging stage, or wherever.Typically, in a preferred method of catalyst support coating and/orimpregnation procedure, there will be high temperature drying and/orcalcining of a coated element in a treating oven for a desired period oftime, which may be for a period of time up to an hour or more.

As heretofore pointed out, the present improved pressure tight chamber,as well as the moving table arrangement adapted to accommodate aplurality of individual chambers, permits a treating system which can becarried out in a rapid manner, as for example in a period of time from 1to 2 minutes, or less, as compared to the slow time consuming procedurewhich would involve a handling of elements in a dipping procedure or aspraying procedure for the various coating and/or impregnating fluids.Specifically, the pressure tight treating chamber permits a rapiddegassifying of an element, or of a plurality of elements, such that thepores of an element are susceptable to rapid coating, as well as theuniform coating of surfaces and pores being accomplished in a manner ofseconds, as compared to the dipping or spraying of an element whereentrapped air within pores must be displaced by gravity flow from liquidcoating materials that must slowly work their way into the surfacepores. The use of high pressure air through and around a particularcatalyst support structure also provides a more rapid removal of excessfluids from surfaces and a more rapid formation of skin drying withouthaving large pore blockage or passageway blockage, particularly whencompared to liquid removal by drippage and by drying carried out in thepresence of a non-pressurized air stream within an unconfined, openzone.

EXAMPLE I

As indicative of the benefit of vacuum treating a ceramic honeycombmember of a rigid crystalline rafractory material, there are data whichcompare the amount of alumina coating retained following an atmosphericpressure dipping procedure and following a vacuum-dipping procedure.

Specifically, in one test procedure, a series of six Corning substrates,or "honeycomb elements" of the EX-20 Type, (cordierite-2MgO.2Al₂o₃.5SiO₂) were subjected to an approximate 2-minute period of dipping inan aqueous alumina slurry having about 25% alumina solids in the slurry.The dipped substrates, or elements, were shaken to remove excess slurryand to insure the unblocking of channels through the substrate. Theaverage wet weight gain for each was approximately 32.32 grams.

In a different test procedure which incorporated vacuum treating, sixEX-20 elements of the same size were each subjected to placement in aclosed chamber having an alumina slurry of the same type and compositionas used for atmospheric dipping. In each instance, the elements werebelow the surface of the slurry and the chamber subjected to a vacuum ofabout 25 inches of mercury for about 1 minute. The vacuum was releasedto permit an atmospheric pressure buildup and then vacuum again appliedfor about 1 minute. During these out-gassing steps air bubbles wereobserved to be rapidly leaving the substrates. In each instance, afterthis vacuum-dip procedure, the substrates were removed from the aluminaslurry and shaken to remove excess slurry and to insure the unblockingof passageways, as with the atmospheric dip procedure. For thevacuum-dipped substrates there was an average net weight gain of about39.6 grams of alumina per element.

This weight gain is quite significant and it is believed that at least apart of the increase in weight was from the resulting flow of aluminacoating into the unblocked surface pores of the vacuum-treatedsubstrates.

EXAMPLE II

In order to further illustrate the use and advantage of the movable wallpressure tight treating chamber in effecting the coating of a catalystsupport member, the following example is set forth. More specifically,there is illustratively described the placement of an alumina slurrycoating onto a rigid skeletal structure, such as a honeycomb elementwith a plurality of parallel passageways, whereby a more porous surfaceis made available for a subsequent impregnation with a highly activecatalytic agent.

Reference to FIG. 2 of the drawing may also be made in connection withthe presentation of this illustrated example. Thus, initially anuncoated element will be loaded into a chamber 38 at the load stationindicated at 64 while the chamber wall is in an elevated position. Theelement is, of course, supported on suitable sharp edge means (such aspins 12 in FIG. 1 of the drawing) whereby there can be good fluid flowdown through the passageways of the element which, in the case of ahoneycomb element, will be in a vertically oriented position. As thetable rotates, there is the actuation of piston means 10 for theparticular chamber 38 such that chamber closing is effected, asindicated by the radial line (1), and there is a pressure tight seal atthe lower edge of the chamber against gasket means on the base portion 4to result in a pressure tight closed chamber. After the closing of thechamber, as indicated by radial line (2), there will be an opening of avacuum control valve which, in turn, connects the interior of chamber 38to a vacuum source to provide for the degassing and evacuation of theelement within the chamber. This operation will normally be carried onfor a short period of time of from 5 to 10 seconds as indicated in thetravel space between radial lines (2) and (3). The vacuum valve is thenclosed and at radial line (4) a liquid alumina slurry control valve isopened such that the interior of the chamber 38 will be filled with asuitably prepared slurry mixture of alumina and water. The slurry flowis continued after the chamber has been permitted to completely fill andas indicated at radial line (5) a dump valve (such as valving means 55below opening 14'0 in base section 4') will permit a continuous flow ofslurry through the passageways of the element to insure adequateinternal coating of the entire support structure. Also, as indicated atradial lines (6) and (7), the dump and slurry valves will close while anair valve is opened to provide for pressurized air on the slurry filledchamber to result in a pressurized forcing of the slurry medium into allpassageways and all of the surface pores of the element. Typically, thepressurized operation will be for a period of 5 to 10 seconds in orderto insure adequate coating of the entire surface of the element.Following the pressurized operation, there will be an opening of thedump valve, as indicated at the radial line (8), while there is acontinuing flow of the pressurized blow-down air. The blow-downoperation will typically continue for some 30-60 seconds in order toinsure a substantially complete removal of all unadsorbed slurry fromthe internal surfaces of the element and also result in a partial dryingof the element, at least to a stage where there will be no substantialgravity flow of slurry material which could block passageways. Then, asindicated at radial lines (9) and (10), there will be a closing of theblow-down air valve, as well as a vent valve opening such that there isa depressurizing of the interior of the chamber and making it ready forthe opening of the chamber wall to remove the coated element.Subsequently, as indicated at radial lines (11) and (12), there will bethe closing of the vent valve and an operation of the air piston 10 toeffect an opening of the chamber wall so that following such openingthere can be the removal of a partially dried and coated element atunloaded station 61. The element may be then placed on conveyor beltmeans 59 for transfer to a further drying and heating step, whichtypically will include high temperature drying of the order of 800° to1000° F. in a calcining oven means.

As heretofore noted, all of the foregoing steps can be carried out in arapid sequential manner where each step will require merely a fractionof a second in some instances and only a few seconds at other instanceswhereby the entire operation, including a relatively long blowdownperiod with pressurized air, will only require some 90 to 100 seconds.By way of summary and for further clarification to indicate typical timeperiods for each stage of contact as the element is carried from stageto stage on the rotating table arrangement, the following tabularlisting of stages and times is set forth.

    ______________________________________                                                         Approximate Time Period                                      Operation        (In Seconds)                                                 ______________________________________                                        Chamber closing  3 - 4                                                        Chamber under vacuum                                                                           8                                                            Vacuum cut off and slurry                                                                      1                                                            valve opening                                                                 Chamber filling with slurry                                                                    10 - 12                                                      Slurry flow      8                                                            Dump valve closing and blow-                                                                   1 - 2                                                        down air opening                                                              Pressurized slurry                                                                             8                                                            Dump valve opening and                                                                         40 - 50                                                      continued air blowing                                                         Dump valve closing and vent                                                                    2 - 3                                                        valve opening                                                                 Chamber opening  3                                                            TOTALS:          84 - 99                                                      ______________________________________                                    

With a total time period which will include unloading a coated elementand loading an uncoated element, which may take another 5-6 seconds,there is a total time period for rotation of the table in the range offrom 90-105 seconds; however, it is to be understood that the timeperiods set forth are merely illustrative and not to be consideredlimiting in any way. The valve opening and closing periods will, ofcourse, depend upon the types of valve mechanisms utilized and themotive power means used in connection therewith to effect the openingsand closing thereof, while the treating periods may vary in accordancewith the type of slurry and/or solution being utilized. Also temperatureand humidity conditions that may be present at the particularenvironment to effect at least a preliminary drying to permit thefurther handling of the element may effect the overall time period.

EXAMPLE III

In a similar apparatus and in a similar procedure such as set forth inthe previous example, there may be the coating and impregnation of analumina coated element or porous refractory inorganic oxide elements,with a suitable active catalyst component. For example, utilizing thesame type of equipment to effect the same sequential stages of contact,there may be the impregnation of an alumina coated honeycomb type ofelement with a noble metal catalyst material, such as withchloroplatinic acid and/or with palladium chloride so as to produce anactive oxidizing catalyst element.

In this instance, the operation will follow all of the sequence of stepsoutlined in Example II, including vacuum degassification, liquid flow,liquid pressurization, and air blow-down so as to provide a partiallydried impregnated element. Also, the periods of contact may besubstantially as listed in the previous example such that again there isa rapid handling of each element to provide complete impregnation to astate ready for high temperature calcining within a period of time whichmay be from approximately 90 to 100 seconds, or perhaps from 60 to 120seconds, depending upon specific contact times for a particular elementand a particular type of contacting solution.

While the foregoing descrption of the apparatus, as well as thedescription set forth in the examples, has been directed to the coatingand impregnation of a rigid honeycomb type of element, it is to be againnoted that more than one element may be placed in the chamber at any onetime or that batches of subdivided particles (such as small spheres orextruded pellets) may well be provided in suitable perforate containermeans and subjected to the multiple stage treatment within thepressurized chamber in order to effect the high speed production ofcatalyst elements. Also, in view of the use of a pressure tight chamberand pressurized fluid flows, there may well be provision for an upwardfluid flow through the chamber to contact a substrate, as an alternativeoperation.

It is to be noted that the terms "element(s)" and "member(s)" aresubstantially synonomous or equivalent terms, as used herein withrespect to the catalyst support structures.

We claim as our invention:
 1. A treating chamber for use in effectingthe multiple stage treatments of catalyst support members to provide acatalyst coating thereon, which comprises in combination,anopen-bottomed liftable housing section, power operated means connectiveto such section for effecting the periodic lifting thereof, a basesection, a seal means for providing a pressure tight seal between saidbase section and the lower periphery of said housing section, spacedsupport pins projecting into the lower central portion of the zone abovethe base section, and providing for an unobstructed fluid flow through acatalyst support member which is placed therein, said housing sectionincluding an elevated seal means provided in a ring-like manner aroundthe interior thereof to provide a fluid seal between the latter and thetop external edge portion of the support member to be placed therein,such that a fluid stream will not flow in the annular space around theinserted member, a fluid drain means from said base section within theconfines of said liftable housing section and said seal means, valvemeans for said drain means, at least one conduit means to the upperinterior portion of said housing whereby a fluid stream may be broughtinto the interior of said housing and into the passageways of saidmember to effect a thorough contacting of the surfaces thereof, andvalving means for said conduit means to regulate various fluid flows tothe interior of said chamber.
 2. The treating chamber of claim 1 furthercharacterized in that said spaced support pins are removably mountedfrom said base section.
 3. The treating chamber of claim 1 furthercharacterized in that the conduit means to the upper interior portionthereof is connected to fluid stream manifold means and valving means,whereby different fluid streams may be introduced sequentially into theinterior of said chamber.
 4. The treating chamber of claim 1 furthercharacterized in that a fluid distributing grid and an open internalsection in the upper interior portion of said chamber provides a fluiddistributing section above the zone where the support member will beaccommodated and above said elevated seal means in order to provideuniform fluid distribution across the entire cross-sectional area of acatalyst support member.